An artificial satellite consists of several systems. Among those, an attitude and trajectory control system directs a satellite to the desired direction and stabilizes the satellite while on duty, against disturbance elements affecting the attitude and trajectory of the satellite. Various sensors need to be used to detect an attitude error occurring due to external disturbances, and advanced apparatuses and technologies are used depending on requirements of accuracy.
The attitude information of the satellite is measured and predicted using various sensors. In this case, it is compared whether the detected attitude information is different from the desired value and then if there is the difference, an actuator is operated to correct the difference.
When the operator intends to direct the satellite to the desired attitude or maintain the satellite at the desired attitude, an actuator such as a reaction wheel is used. The actuator (vibration source) may cause a high frequency micro vibration. The high frequency micro vibration acts as one of the main factors of reducing directional stability of the satellite or performance of various systems mounted. Therefore, a high resolution satellite uses a vibration controller reducing the micro vibration.
Generally, the vibration controller may be classified into a passive controller, an active controller, and a semi-active controller.
The active vibration reduction apparatus is an apparatus for reducing a vibration using an active element, and uses an appropriate control technique according to a frequency range to be isolated and system characteristics. In this case, there is a problem in that the active vibration reduction apparatus needs to be designed again when a target frequency to be isolated is different from the designed ranges.
The passive vibration reduction apparatus is a technology of dispersing energy generated from the vibration source. The passive vibration reduction apparatus is easily implemented, and when the target frequency to be reduced is defined, the passive vibration reduction apparatus has excellent vibration reduction characteristics and functional reliability in a high frequency region, and thus has been mainly used as the apparatus for reducing vibrations of an artificial satellite.
Generally, the vibration controller has mainly used an elastomer as a vibration reduction material. The vibration controller is installed between the vibration source and a structure, and reduces a vibration generated from the vibration source in the elastomer that is an elastic body, thereby the vibration does not influence the structure.
Korean Patent Laid-Open Publication No. 10-2008-0085180 (Elastomer-based modular multi-axis vibration/shock isolation device, published on Sep. 23, 2008) discloses a vibration reduction apparatus using an elastomer. Generally, in the vibration reduction apparatus using an elastomer, the elastomer is mainly coupled by an adhesive. The adhesive type vibration reduction apparatus may have a weakened adhesive force depending on environment, vibration conditions, or the like. In particular, when an adhesive is used under poor environment such as space environment, more problems may be caused. If the elastomer is separated due to the weakened adhesive force, the vibration reduction apparatus does not perform its own function, and therefore the performance of the artificial satellite may be reduced.